The first identification of spring viraemia of carp (SVC)
in the US has been made in a koi hatchery in Kernersville, North Carolina.
SVC is a disease of several species of cyprinid fishes caused by Rhabdovirus
carpio.

Cyprinid fishes are produced as food fish, ornamental
fish (koi and goldfish) and baitfish. In 1998 in the US, 39 facilities
produced food carp, 115 produced koi, 65 produced ornamental goldfish, and
34 produced feeder goldfish. The total value of farm sales was $21.2
million. The US exported $1.8 million worth of live carp in 2001,
almost exclusively to Canada.

In response to the US SVC finding, all fish in the affected
ponds have been slaughtered and the affected ponds have been drained. A
surveillance program has been instituted and the hatchery has been placed under
quarantine. The North Carolina Wildlife Commission has been contacted
to test rivers and tributaries that receive effluent water from the hatchery. Several
of the susceptible species have been reported in the wild in waters of west-central
North Carolina .

How extensive is the situation?

The
first identification of spring viraemia of carp (SVC) in the US has been
made in a koi hatchery in Kernersville, North Carolina. Koi are a colored,
ornamental strain of the common carp, Cyprinus carpio. SVC was
first suspected in April 2002, when the hatchery experienced a 10% per week
death rate in juvenile koi, which were being observed as part of a quality
control program. Diagnostic samples were first sent to the University
of Arkansas Pine Bluff Laboratory, an APHIS approved diagnostic laboratory,
then forwarded to the OIE reference laboratory located in Weymouth,
United Kingdom, where the diagnosis was confirmed on July 5, 2002 . The
premises where infected fish were found consisted of 202 ponds divided among
6 locations. Infected fish were detected in a total of 4 ponds. Of
150,000 koi in the 4 ponds, 15,000 died and the remaining 135,000 were depopulated. The
4 affected ponds were drained.

The hatchery is no longer experiencing signs of SVC in
any of the other ponds or processing facilities. A foreign animal disease
investigation is underway, but the potential source of infection has not been
identified. Samples from all remaining ponds are being sent to theUniversity
of Arkansas Pine Bluff Laboratory. Tanks and equipment have been disinfected. A
surveillance program has been instituted and the hatchery has been placed under
quarantine. The North Carolina Wildlife Commission has been contacted
to test rivers and tributaries that receive effluent water from the hatchery.

What Species are Susceptible to Spring Viraemia of
Carp virus?

According to the OIE, susceptible host species of Spring
Viraemia of Carp virus (SVCv) include cyprinid fishes, specifically the common
carp (Cyprinus carpio), grass carp (Ctenopharyngodon idellus),
silver carp (Hypophthalmichthys molotrix), bighead carp (Aristichthys
nobilis), crucian carp (Carassius carassius), goldfish (Carassius
auratus), tench (Tinca tinca), and sheatfish (Silurus glanis). SVC
is on the OIE Fish Diseases Commission list of ‘Diseases notifiable to the
OIE’ and it is also included on OIE’s List B. SVC has previously been
reported in western and eastern Europe and Israel.

What is Spring Viraemia of Carp?

Spring Viraemia of Carp is systemic, acute and highly
contagious. SVC is caused by Rhabdovirus carpio, which is a typical
bullet shaped virion about 60-90 nm wide and 90-180 nm long and which bears
a regular surface array of glycoprotein spicules. The virus adsorbs to
cellular plasma membranes and enters the cell by receptor-mediated endocytosis. The
gill is the most common portal of entry. Infected cells develop cytoplasmic
inclusion bodies and mature virions are released by budding from the plasma
membrane. SVC is transmitted horizontally and by blood sucking parasites
such as the carp louse (Argulus foliaceus) and leech (Pisciola geometra). SVC
typically occurs when water temperatures are less than 18°C
and is most common in the spring. At 20-22°C,
infection occurs but clinical disease does not develop. When clinical
disease is present, mortality ranges from 30 to 70%. Affected fish often
seek slow moving water or lie on the bottom. As the disease progresses,
fish become non responsive to external stimuli, sluggish, swim on their side
and rest in abnormal positions. The skin becomes darkened and the belly
swollen. Petechial and ecchymotic hemorrhages and exopthalmos are common
and reflect viral predilection for endothelium, resulting vascular leakage
and loss of fluid balance. Long, thick, mucoid casts may be observed
from the vent. Successful treatment of infected fish has not been demonstrated. There
is no approved vaccine for SVC in the US. Control measures include iodophore
disinfection of eggs and periodic chemical and physical disinfection of ponds
and equipment. Minimizing stress and overcrowding and sanitary disposal
of dead fish are also recommended. Raising fish at a water temperature
of 19-20° C has been suggested,
but the cost of heating water in a temperate climate can be prohibitive.

Source: OIE Disease
Information Report, Spring Viraemia of Carp and other Viral Diseases and
Agents of Warm Water Fish by N. Fijan, USDA Area Veterinary Office in North
Carolina.

What is the size of the carp/koi
and the goldfish industries in theUSand
inNorth Carolina?

In 1998, the US
had 39 facilities that produced carp as a food fish, with a total sales value
of $1.3 million (Table 1). North Carolina had only 1 facility that
produced stocker carp intended to be raised as food fish.

A total of 115 facilities produced
koi in the US
in 1998. The total sales value of these facilities was $3.9 million. Ornamental
goldfish were produced in 65 facilities, with sales totaling $6.7 million. North
Carolina had 6 facilities that produced koi,
with a sales value of $137,000, and 3 facilities that produced ornamental goldfish,
with undisclosed sales value.

Goldfish are also used as baitfish. Thirty-four
(34) facilities produced feeder goldfish in theUS in
1998, with sales totaling $9.3 million. North
Carolina had 2 facilities that produced
feeder goldfish.

Table 1: Number of facilities and value of sales
for affected fish in theUS andNorth Carolina, 1998

Type of fish

Number of facilities

Value of sales ($ million)

US total

NC

US total

NC

Food carp

39

1

1.3

-

Koi

115

6

3.9

0.137

Ornamental goldfish

65

3

6.7

-

Feeder goldfish

34

2

9.3

-

- = withheld to avoid disclosing data for individual farms

Source: USDA,
NASS, 1998 Census of Aquaculture

What is theUSA’s
place in the international market for affected fish?

The US produced
11,739 metric tons of carps, barbels, and other cyprinids in 1999, accounting
for less than 0.1% of world production.

Source: United Nations
FAO

What are theU.S. exports of affected
fish?

The US exported live carp worth $1.8 million and $738,000
in 2001 and January through April 2002, respectively. These fish were
exported almost exclusively to Canada, with only a minor sales value to
Mexico
in 2001. None of the live carp that were exported in 2002 or 2001 originated
in North Carolina.[1] Goldfish
export data are not available.

Table 2: US exports of live carp, 2001 and January-April
2002

Product

$ value (million)

2001

2002 (Jan-Apr)

Live
carp

1.824

0.738

Source: World Trade
Atlas

Are susceptible species found in the wild in west-central
North Carolina?

In 2000, a review of the diversity and distribution of
native freshwater fish of the southern United States, including those of the
Pee Dee River basin, was published. Of the 662 native freshwater and
diadromous fishes and 24 marine fishes listed, none were of the same genus
as those listed as susceptible by the OIE to spring viraemia of carp.

Non-native susceptible fish have been detected in the
waters of west-central North Carolina including the grass carp, common carp,
goldfish, and tench. The overall size of the population of these non-native
species within North Carolina is unknown.

Sources: USGS @ nas.er.usgs.gov/fishes/accounts, July 17, 2002;

Diversity, Distribution,
and Conservation Status of the Native Freshwater Fishes of the Southern
United States. Published
in Fisheries, October 2000.

CEI’s plans for follow up:

CEI will continue to monitor the situation but has no
plans at this time to issue additional reports. If you seek more information
or wish to comment on this worksheet, please reply to this message or contact
Robert Harris at (970) 494-7327 or Christine Kopral at (970) 494-7325.

[1] The
state-specific export data report the state from which the export began its
export journey. This is not necessarily the state in which the merchandise
is produced.